Propeller guard



Nov. 12, 1929. w...1. DANcKwART PROPELLER GUARD Filed May '7, 1929 M INVEN TOR.

Patented Nov. 12, 1929 WILLIAM a'. DANCKWART, orV comune-, CALIFORNIAPROPELLEB GUARD Application led May 7,

` This invention relates to certain new and useful improvements inpropeller guards and is l'especiall designed for association with `thepropel er of aircraft, such as an aeroplane, and has for its' primaryobject to protect the propeller blades against injury by coming .inContact with flying dbris, birds or other objects in the air, but in nowayy tending to lessen the efficiency of the propelling force of theblades.

With the above and other objects in view that will become apparent asthe nature of the invention is better understood, the same consists inthe novel form, combination and arrangement of parts hereinafter morefully described, shown in the accompanying drawing and claimed. t

In the drawing j Figure 1 is a fragmentary side elevational View of aflying machine equipped with the propeller guard constructed inaccordance with the present invention;

Fi ure 2 is a fragmentary top plan view of t e :flying machine equippedwith the guard;

Figure 3 is an enlarged fragmentary front elevational view-showing theguard or screen positioned forwardly of the propeller blades; and jFigure 4 is a vertical cross-sectional view through the propeller guardshowing its relationship to the propeller blade.

As illustrated, the flying machine comprises a fuselage 1 provided withupper and lower wings 2 and 3 and a forwardly positioned propeller shaft4 upon which a propeller blade 5 is anchored. The mounting of the propeller blade 5 upon the propeller shaft 4 is of the usual construction asshown in 4o section in Figure'4, while the propeller shaft 4 carries aforward extension 4a projecting forwardly of the propeller blade.

The guard for the propeller blade. comprises a pair of concentric rings6, one within the other and slightly spaced apart for purposes presentlyto appear, the rlngs 6 carrying a forwardly arched cross strip 7extending between diametrically oppositeI points with a semi-cylindricalbearing collar 8 housingthe ball bearing race 9 into 1929. Serial No.361,183.

which the propeller shaft extension 4a eX-- tends. The connectionbetween the propeller rblade guard and flying machine comprises a pairof upper connecting rods 10 anchored at their inner ends as at 11 to the55 forward edge of the upper wing 2 and at their forward ends asat 12 tothe upper sides of the rings 6 of the guard, thev supporting bars 10being forwardly convergent. Similar supporting rods 13 have their innerends 60 connected as at 14 to the forward end of the fuselage 1 whilethe forward ends of the rods 13 are anchored as at 15 to the lower sidesof the rings 6. A screen guard 16,4

substantially of conical formation as shown in Figure 4 is carried bythe guard frame withthe peripheral edges thereof extending between therings 6 and anchored position by the fastening devices 12 and 15 for thebrace rods 10 and 13 while the cen- 70 tral portion of the screen gaurd16 is anchored to the center bearing collar 8 by the clamping rin 17 asshown in Figure 4. The screen v guard eing positioned inwardly of theforwardly arched cross strap 7 'as shown in 75 Figure 3. F

The screen may be of the desired mesh so that efficiency of thepropeller blade will not be impaired while injury to the propeller blade5 will be eliminated as the screen guard 80 will prevent the propellerblade from coming into. contact with an objects moving in the air,suchas birds or ying dbris. The upper supportin rods 10 for the guardframe converge orwardly while the lower g5 supporting rods 13 divergeforwardly, resulting in a strong and substantial support for the guardframe and holding the same rigidly positioned out of the path ofmovement of the propeller4 blade 5, the position- 90 ing of thesupporting rods 10 and 13 elimi-l nating 'any possibility of distortionof the guard frame sothat injury to the propeller blade from the guardis eliminated.

From the above'detailed description of the 95 invention, it is believedthat the construction and operationthereof will at once'be apparent, andwhile there is herein shown and described the preferred embodiment ofthe present invention, it is nevertheless to be understood that minorchanges may be made therein without departing from the spirit and scopeof the invention as claimed.

I claim l. The combination with the propeller ofan aircraft, of a screenuard permanently positioned forwardly of t e propeller,.a forwardextension on the propeller shaft upon which the guard is mounted, andbrace rods extending between the peripheral edge of the guard and theaircraft.

2. The combination with the propeller of an aircraft, of a screen guardpermanently positioned forwardly of the propeller, in enclosing relationtherewith, a forward extension on the propeller shaft upon which theguard is mounted, and brace rods extending between the peripheral edgeof the guard and the aircraft.

3. The c ombination with the propeller of an aircraft, of na screenguard permanently positioned forwardly of the propeller, a forwardextension on the propeller shaft upon which the guard is mounted, andbrace rods extending between the peripheral edge of the guard and theaircraft, upper and lower sets of brace rods extending between theperipheral edge of the guard and the aircraft, the upper set of rodsforwardly converging and the lower set being forwardly divergent.

4. The combination with t e propeller of an aircraft, of a screen guardpermanently positioned forwardly of the propeller, ip enclosing relationtherewith, a forward eX- tension on the propeller shaft upou which theguard is' mounted, and brace rods extending between the peripheral edgeof the guard and the aircraft, upper and lower sets of brace rodsextending between the peripheral edge of the guard and the aircraft, theupper set of rods forwardly converging and the lower set being forwardlydivergent.

'In testimony whereof I aiiix my signature.

WLLIAM J. DANCKVVART.

